Submission #1051574

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051574		Gromp15	Comparing Plants (IOI20_plants)	C++17	25 / 100	4037 ms	8076 KiB

plants

#include <bits/stdc++.h>
#include "plants.h"
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using namespace std;

int n, k;
vector<int> got;
vector<int> r;
vector<vector<bool>> can;

void init(int _k, std::vector<int> _r) {
	k = _k;
	r = _r;
	n = sz(r);
	if (2 * k > n) {
		got.resize(n);
		vector<bool> vis(n);
		for (int i = 0; i < n; i++) {
			vector<int> good;
			for (int j = 0; j < n; j++) if (!r[j] && !vis[j]) {
				bool ok = 1;
				for (int z = 1; z < k; z++) {
					int idx = j - z;
					if (idx < 0) idx += n;
					if (!vis[idx] && !r[idx]) {
						ok = 0; break;
					}
				}
				if (ok) {
					good.emplace_back(j);
				}
			}
			if (good.empty()) break;
			for (int v : good) vis[v] = 1;
			assert(good.size() == 1);
			for (int c : good) {
				got[c] = n - i;
				for (int j = 1; j < k; j++) {
					int idx = c - j;
					if (idx < 0) idx += n;
					r[idx]--;
				}
			}
		}
		r = _r;
		return;
	}
	if (n <= 300) {
		can.resize(n, vector<bool>(n));
		for (int t = 0; t < n; t++) {
			r = _r;
			vector<bool> vis(n);
			for (int i = 0; i < n; i++) {
				vector<int> good;
				for (int j = 0; j < n; j++) if (!r[j] && !vis[j]) {
					bool ok = 1;
					for (int z = 1; z < k; z++) {
						int idx = j - z;
						if (idx < 0) idx += n;
						if (!vis[idx] && !r[idx]) {
							ok = 0; break;
						}
					}
					if (ok) {
						good.emplace_back(j);
					}
				}
				if (find(all(good), t) != good.end()) good.erase(find(all(good), t));
				if (good.empty()) break;
				for (int v : good) vis[v] = 1;
				for (int c : good) {
					for (int j = 1; j < k; j++) {
						int idx = c - j;
						if (idx < 0) idx += n;
						r[idx]--;
					}
				}
			}
			for (int i = 0; i < n; i++) can[t][i] = vis[i];
		}
	}
}

bool win(int x, int y) { // can x be used before y
	if (2 * k > n) {
		int d = (x - y + n) % n;
		if (d < k && !r[y]) return 0;
		return got[x] > got[y];
	}
	return can[y][x];
}

int compare_plants(int x, int y) {
	int w1 = win(x, y), w2 = win(y, x);
	assert(w1 || w2);
	return w1 && w2 ? 0 : w1 ? 1 : -1;
}

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 13
• Subtask 4: 0 / 17
• Subtask 5: 11 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25